Impact of Daylight on Period 2 Protein and Glycolytic Enzymes in Human Buccal Mucosa and Blood Samples

Damage to the heart caused by a myocardial infarction (heart attack) occurs most often during the early morning hours (6AM). Thus, the involvement of the circadian system (circa= approximately day) has been suggested. The circadian system in humans or animals is based on the rotation of the earth with day and night phases. When humans (or animals) wake up light shines in their eyes and the body receives a signal that the day starts. For the human body it means that certain proteins (named clock, period etc) are produced. The protein that determines the length of a day (awake and sleep period) is called Period 2 (Per2). Recent data indicated that the Per2 protein in hearts from mice is induced after daylight exposure (daylight with an intensity comparable to a bright day at the beach was used, approx. 10 000 LUX). This more Per2 was able to protect the heart from being damaged by no blood going to the heart (protection from a heart attack). This protection was based on a more efficient use of sugars (carbohydrates). Thereby the heart needs less oxygen. Current data indicate that human Per2 is also induced by light exposure and can be detected in human plasma samples.

In this study Per2 transcript and protein levels will be analyzed in patients that just experienced a heart attack with and without intense light (daylight) therapy utilizing blood samples (erythrocytes and leukocytes).